The invention relates to a method for operating a motor vehicle, in particular the supply of power of a motor vehicle, during a collision and/or during a time period following a collision, wherein the motor vehicle is at least partially deenergized. In addition, the invention relates to a motor vehicle with at least one control device configured to carry out the method.
Active and passive safety systems, which are designed in particular for collision avoidance and/or collision mitigation, are already known in the prior art. For example, such systems can verify, usually based on a collision probability, whether the risk of a collision exists, so that various measures can be attempted to avoid a collision and/or to at least to minimize the damage resulting from a collision. Measures can include active driving interventions, but may also include also measures enhancing the overall safety of the vehicle, such as raising an engine hood, and/or issuing warnings and/or instructions, as well as controlling additional vehicle systems, for example for preconditioning. For example, it is known to adapt the operating parameters of vehicle systems in advance of a potential or unavoidable collision with respect to the particular situation, so as to, for example, reduce delay times and the like.
When a collision is inevitable, i.e. when the dynamic possibilities of the motor vehicle through driving interventions are no longer adequate to avoid a collision with a collision partner, then other problems may arise after the initial collision, for example, consequential collisions. However, it has been proposed in today's motor vehicles to completely deenergize the motor vehicle when a collision exceeds a certain collision severity, for which, for example, at least one collision severity value can be considered, which must be greater than a threshold value, meaning to disconnect at least one electrical power source of the motor vehicle, in particular at least one battery, from all loads. This approach should not only prevent dangerous high voltages for the driver caused by damage in the energy supply system of the motor vehicle or dangerous situations caused by the continued operation of electrical components, especially fires, but also protect rescuers that may have to work on the motor vehicle. Accordingly, motor vehicles are known where the main power is disconnected from the loads when the collision severity value exceeds a threshold value, usually already during, or at least immediately after the collision, to ensure that the safety system disconnecting the energy does not fail.
In this way, however, the safety systems of the motor vehicle are also deenergized, so that the safety systems can no longer be triggered again, in particular following a first accident, i.e. the collision. This increases the severity of subsequent collisions, since accident-severity-mitigating measures for a subsequent collision can no longer be initiated after the first collision.
It was proposed in this context in the later published German patent application DE 10 2011 115 223.0, to provide in a method for operating a safety system of a motor vehicle, in particular a system for collision mitigation in an unavoidable collision, that in an unavoidable collision, the safety system determines a collision target trajectory of the motor vehicle to be realized after the collision and having a definite target position with respect to consequential collisions, and carries out at least one autonomous and/or assistive driving intervention in the form of at least one longitudinal guidance intervention and/or lateral guidance intervention for realizing the target trajectory, in order to increase the safety with respect to subsequent collisions after a first collision. The goal is to ultimately assume a safe target position with the lowest possible consequential collision probability.